Report On Mechanical Engineering Summer Internship

General Description of the Company

Arçelik A.Ş is a Turkish international company considered to be one of the leading companies in the world in the field of manufacturing, designing and distributing consumer’s goods and white good. The company has been founded by Vehbi Koç and is owned by Koç family one of the wealthiest families in Turkey under the primary parent holding Koç Holding. i. Brief history Arçelik established in 1955 and got firstly in white goods in 1959 as a maker of washing machines as a leading Turkish industry. After that, first refrigerator got produced in 1960. In 1968, Arçelik transferred to a new fabrication plant in Çayırova, Kocaeli province. In 1975, Arçelik continued to expand and established its Eskişehir factory of refrigerators. Afterward, Izmir vacuum cleaner factory and Ankara dishwasher factory were opened in 1979 and 1993 respectively.

Arçelik experienced period of prosperity in the year of 1999 by founding sub-companies for manufacturing and assisting Arçelik brands with varied consumer goods, mechanical parts and electronics. In the year of 2007, The German home appliances and multimedia manufacturer Grundig become a part of Arçelik group.

In the recent time, Arçelik now owns and produces products for many local and international brands like: Arçelik, Beko, Arctic, Altus, Blomberg, Leisure, Grundig, Dawlance, ElektraBregenz, Flavel and Defy

About the Production Plant

ARÇELİK A.Ş. Bolu Cooker and Heating Devices factory is a factory at the western region of Bolu province in Turkey that has been established in 1996 under the name of Ardem. This factory become then two factories as an extension for the production under the name of Arçelik cooking appliances factory.This factory has various tasked departments and the engineering departments are: Production, Assembly Factory 1, Assembly Factory 2, Assembly Preparation, Packaging, Mechanical Shop, Maintenance, Research and Development, Quality and Assurance.

The factory is known for assembling cooking appliances and manufacturing sample parts for them like: Built-in ovens (BI Ovens), Free standing ovens (FS Ovens), Built-in cooktops, Portable cooktops, Kitchen ventilation.

The Free standing and built-in ovens are manufactured, assembled, packaged and stored in the first factory. In a similar way, built-in ovens, portable cooktops and kitchen ventilation are manufactured, assembled, packaged and stored in the second factory. Some of the sample parts that the production plant manufactures are: Oven Chassis, Glass Doors Profiles, Oven Plates, Cooktops Frames, Panels. These are mostly the pieces that are manufactured in the factory, other small parts and necessary parts are coming from the distributors.

Analysis of Manufacturing Techniques

It’s important to address that most of the manufacturing processes are done autonomously. Mainly, The machines are components of an autonomous system that makes multi-manufacturing process orderly, so the final product can be reached quicker and at the same time production rate increases. The most observed manufacturing techniques were:

• Pressing: Pressing machines are used to make the oven chassis sheets and oven panels. Additionally, pressing is made by robotic arms to press glass doors to side profiles after gluing.
• Welding: Welders are automated and welds the gaps in the cooktop frames and chassis.
• Bending: Bending operation is also automated and its used mostly to shape the chassis, panels, cooktop frames and glass doors’ side profiles.
• Drilling: Drilling operation is made autonomously. Drills make holes and gaps inside most of the sample parts to leave places for fasteners or attachments for the assembly.
• Gluing: Gluing is made mostly for glass doors to let it stick with side profiles using silicon gluing.
• Enameling: Enameling is used to give a better surface finish and durability to the panels.
• Painting: Painting is used for painting all sample parts to give better surface finish.

Pressing

There are huge presses that shape the processed sheet metals from normal sheet rolls. The plain sheet metal is cut by cutters to give the precise necessary dimension for making processed sheet for chassis and panels that will later be bend and have further operations to lead lastly to final products. After sheets get cut, the pressing starts with dies that has specific shapes and can be modified in the mechanical shop depending on the use and model produced. After these sheets are pressed many times (mostly four) with different dies for each pressing cycle.

Finally, we reach the last processed sheet that might be transported to another automated system of machines or the pressing system itself has already bending and drilling machines after pressing so it can finalize the products directly. Mostly the products that need to be transported are oven chassis sheets and the ones that can be finalized are the panels. This is mostly the pressing operation inside the factory.

Bending

Bending operation can be done to bend many processed samples to reach a final product. The shape of bending is mostly rectangular for most of the sample parts. For instance, the chassis’ processed sheets are bended to form a shape of a rectangular box (chassie shape) using multiple automated bending machines. Another example can be cooktop frames, processed thin sheets comes to the rectangular bending machine to form the squared or rectangular shape of cooktop frame. Lastly, the oven glass door profiles. Inside the multi-tasked automated manufacturer of glass door profiles, there are benders that bends the side of processed sheet rolls to form the shape of the profile. We can’t give a certain number of bending machines since they exist as components of multiple multi-tasked manufacturing machines inside the factory.

Welding

TGI automated welders are mostly the type of welders inside the factory. For instance, after the cooktop frame part is made after square bending, an automated welder closes the gap by welding it to make it as a one closed profile.

In case of chassies, the welders weld the rectangular box (the solid chassie) to sidery frame in front of the chassie so it become as a final processed chassie. Manual welding can be also observed in the creation of cooktop frame as they put some pieces at the angles for further assembly of cooktop. The number of observed automated welding machines was 4 and number of manual welders was 2.

Drilling

Drilling is made autonomously. Drills make holes and gaps inside most of the sample parts to leave places for fasteners or attachments for the assembly. As the drilling operation was automated, it was hard to give a certain number of bending machines since they exist as components of multiple multi-tasked manufacturing machines inside the factory.

Laser Cutting

Laser cutting machines can be seen in the second factory, they are about 3 laser cutting machines shapes many smaller sample sheets that will be used later for assembly of the sample products.

Gluing

Gluing is made manually and autonomously to stick glass doors with side profiles using silicon gluing. FANUC robotics arms are used fordipping the injector in silicon and sucks it, then it releases the silicon concentrate in the place of gluing. The place of gluing can be reversed (whether the glass door itself or the profile) depending on the model and size of the glass door. These robotics arms are components of 3 main multi-operational autonomous systems called CTF systems from an Italian producers. So there are 3 CTF machines at assembly preparation department which is my assigned department to work in.

Painting

Painting is used for painting all sample parts to give better surface finish, The main colors used are mostly black and white depending on the sample part produced but mostly black color can be observed. There is also the printing part where the test and figures of the panel along with the logo of the product is printed. Printing is done manually by painting some>>,,, by brush on top of the panel so the text and figures and logo get printed. After that, the panels goes through UV rays machine used to let the paint stick and hard to remove by any condition.

Enameling

Enameling process is basically the process of injecting melted thin layers of glass to the parts to give it a bit of shine and durability. This process is made at a high temperature after the sample parts is painted. After the enameling is made in the furnaces, processed products exit the furnace to cool down and stored to go

Sample Work Pieces & Cost Analysis

Roll forming automated machine works as a collective and consequent manufacturing machine that combines many manufacturing techniques in order basically to change sheet metals into ready to paint and use profiles. These profiles are used as essential components for the assembly of the ovens’ doors. This machine manufactures the same component but with different mechanical designs depends on the type and the model of the oven. The place of these profiles on the oven glass door can be shown here:

The three different profile models to be analyzed are 215300048, 2153000161 and 2153000162, these are profiles differ in dimensions and number of holes drawn as well as direction of placement (left of right). Sample profile before painting can be shown beside. And the automated process that these 3 different profiles go through are as follows:

Rolling of sheet metal

Metal sheet rolls goes inside a rolling machine to adjust this sheet to the desired thickness.

Holes Drilling

Drilling the holes are done by automated drills to drill circle or squared shaped holes so further pieces or fasteners can be placed inside the holes.

Putting separations by cutting

Putting a marked separation at each fixed distance so between each separation we have the processed sheet to create one profile. This separation is basically a cut that has semi-line shape.

Bending of sheets

Bending of the side of the processed metal is done to shape it as the shape of the profiles so it will look rectangular.

Separation of bended sheets by cutting

Now automated saws cut the places of separations to have each desired profile ready.

Sorting

Sorting are made manually if the box has many different models.

Painting

Profiles are painted black at a high temperature and then cooled at room temperature and stored for gluing and assembly.

Gluing

Silicon gluing are done to profiles with the glass doors using CTF’s as mentioned previously in details for gluing operation in part III-ii.

Assembly

Conclusions and Observations

The internship was an extraordinary experience benefiting me in my academic and work aspects. I learnt more about the technical and engineering works and problems that big companies like Arcelik cares about most. When I started my internship, I was assigned to my department which is ‘Assembly Preparation’ and I had my advisor and my manager in the department. In addition to the manufacturing methods and sample parts detailed analysis made as mentioned before, the department gave two projects for me and my colleague who is also an intern in the same department. The first project was dealing with the improvement of products existing conveyor carriage and transfer system. The second project was a design optimization for an oven profile to avoid silicon overflowing outside this profile.

For the first project, we had our existing conveyor system as well as the transfer systems. There was a critical part of the conveyor system that has a high waiting time for the products. This problem appeared because of the lack of efficiency of the current transfer system as well as lack of efficiency of the existing barcode reading sensor system. The transfer system sorts the built-in ovens (BI) ovens and free standing (FS) ovens so BI ovens goes to D packaging line and FS ovens goes to the other packaging lines as can be seen in the appendix (). The existing transfer system has pop up rotating cylinders and we have suggested a normal pop up transfer system since it will be faster and will provide more stock area to BI ovens provided that we put a new conveyor belt as shown In appendix (). Additionally, the existing barcode reading system consist of only one barcode reading sensor so the product needs to stop each time before sorting so it can read the product type (BI or FS oven) from the barcode. As a solution, we have suggested two sensors barcode reading system so the waiting time for products for reading before sorting will be reduced since two products is already knowing where they will go directly without the wait for the second one for barcode reading. Finally, we have suggested the side railway lines after each transfer or rotation so the products can go straightly oriented without misorientation that adds friction to the transfer system and delay the carriage. These railway lines have free rotated small plastic cylinders that let the goods orient in a straight line when the products hit these lines.

For the second project, we have noticed that the silicon is over flowing after pressing the glass doors to the profiles. Change of the profile shape was considered but with many restrictions in volume and shape of this profile along with avoiding any additional operational cost. We have thought of some solutions but finally the existing profile shape was currently the optimum one that doesn’t need any urgent immediate change.

During these projects, I have developed many of my technical and engineering skills. I have learnt to know how to think more critically and analytically as well as to consider the full picture of each problem. The guidance support and help of my advisor was really high and he didn’t hesitate to answer any question or doubt. My colleague, advisor and manager were very helpful to me during my internship and I give them my thanks and regards to what they have done. Arcelik internship was a unique experience that added a lot to me technically, academically and socially. It gave me more insight into the engineering and technology that lies behind big industries.